Advanced Font Features

Font technologies like Open Type and AAT provide a number of advanced  
typographic features, i.e. stuff known from print or handwriting, but  
uncommon to electronic typesetting. Not all of them have counterparts  
in CSS yet.

Should they? How?

CSS would either provide a generic interface for selecting features  
by the author or new properties and values would be inspired of what  
is made available by the specifications (whether or not font  
designers and text rendering library developers choose to implement).

   table   {font-style: option("tnum")}

or

   code    {ligation: none;}
   kbd>kbd {glyph-style: isolated;} /* a key */
   table   {number-style: tabular non-lining;}
   .sig    {font-family: cursive; serif-style: swash; ligation: full;}

...

PS: As far as I know there is nothing like italics in East-Asian  
typography. Oblique can be simulated by automatic slanting. Would it  
be acceptable for Japanese to switch display between Katakana and  
Hiragana for "font-style: italic"?